I used some tools to recreate the Hashcodes and check ist.
All Checsums MD5, SHA1 and CRC are correct. It should realy be the same file that is on my harddrive. But AOM keeps saying that the file is unknown.

You can try avdump with the -0123e options and see what hashes it reports. Also if you could post what AOM thinks the hash is that may be helpful (you can get it from the log tab, you may need to remove the file from the known files to force it to be rehashed). The file is in the database as AOM Verified, which means that AOM successfully hashed the file before, so there should not be an issue with that specific file... As long as you are at it, you may as well use avdump to get all the bitrates and creq the file.

Well the problem seems to be solved after remove and readd the file AOM found it in the Database.
I had an open creq for this file (nothing with the hashcodes) which is granted now maybe thats the reason why the file is now known correctly.
Maybe a little mixup in the database with the change to UTF-8 encoding. Who knows, however it's working now.